return 0;
}
-/*
- * Allocate pages which are contiguous in machine memory.
- * Returns a VA to where they are mapped or 0 on failure.
- *
- * addr_bits indicates if the region has restrictions on where it is
- * located. Typical values are 32 (if for example PCI devices can't access
- * 64bit memory) or 0 for no restrictions.
- *
- * Allocated pages can be freed using the page allocators free_pages()
- * function.
- *
- * based on Linux function xen_create_contiguous_region()
- */
-#define MAX_CONTIG_ORDER 9 /* 2MB */
-unsigned long alloc_contig_pages(int order, unsigned int addr_bits)
-{
- unsigned long in_va, va;
- unsigned long in_frames[1UL << order], out_frames, mfn;
- multicall_entry_t call[1UL << order];
- unsigned int i, num_pages = 1UL << order;
- int ret, exch_success;
-
- /* pass in num_pages 'extends' of size 1 and
- * request 1 extend of size 'order */
- struct xen_memory_exchange exchange = {
- .in = {
- .nr_extents = num_pages,
- .extent_order = 0,
- .domid = DOMID_SELF
- },
- .out = {
- .nr_extents = 1,
- .extent_order = order,
- .address_bits = addr_bits,
- .domid = DOMID_SELF
- },
- .nr_exchanged = 0
- };
-
- if ( order > MAX_CONTIG_ORDER )
- {
- printk("alloc_contig_pages: order too large 0x%x > 0x%x\n",
- order, MAX_CONTIG_ORDER);
- return 0;
- }
-
- /* Allocate some potentially discontiguous pages */
- in_va = alloc_pages(order);
- if ( !in_va )
- {
- printk("alloc_contig_pages: could not get enough pages (order=0x%x\n",
- order);
- return 0;
- }
-
- /* set up arguments for exchange hyper call */
- set_xen_guest_handle(exchange.in.extent_start, in_frames);
- set_xen_guest_handle(exchange.out.extent_start, &out_frames);
-
- /* unmap current frames, keep a list of MFNs */
- for ( i = 0; i < num_pages; i++ )
- {
- int arg = 0;
-
- va = in_va + (PAGE_SIZE * i);
- in_frames[i] = virt_to_mfn(va);
-
- /* update P2M mapping */
- phys_to_machine_mapping[virt_to_pfn(va)] = INVALID_P2M_ENTRY;
-
- /* build multi call */
- call[i].op = __HYPERVISOR_update_va_mapping;
- call[i].args[arg++] = va;
- call[i].args[arg++] = 0;
-#ifdef __i386__
- call[i].args[arg++] = 0;
-#endif
- call[i].args[arg++] = UVMF_INVLPG;
- }
-
- ret = HYPERVISOR_multicall(call, i);
- if ( ret )
- {
- printk("Odd, update_va_mapping hypercall failed with rc=%d.\n", ret);
- return 0;
- }
-
- /* try getting a contig range of MFNs */
- out_frames = virt_to_pfn(in_va); /* PFNs to populate */
- ret = HYPERVISOR_memory_op(XENMEM_exchange, &exchange);
- if ( ret ) {
- printk("mem exchanged order=0x%x failed with rc=%d, nr_exchanged=%lu\n",
- order, ret, exchange.nr_exchanged);
- /* we still need to return the allocated pages above to the pool
- * ie. map them back into the 1:1 mapping etc. so we continue but
- * in the end return the pages to the page allocator and return 0. */
- exch_success = 0;
- }
- else
- exch_success = 1;
-
- /* map frames into 1:1 and update p2m */
- for ( i = 0; i < num_pages; i++ )
- {
- int arg = 0;
- pte_t pte;
-
- va = in_va + (PAGE_SIZE * i);
- mfn = i < exchange.nr_exchanged ? (out_frames + i) : in_frames[i];
- pte = __pte(mfn << PAGE_SHIFT | L1_PROT);
-
- /* update P2M mapping */
- phys_to_machine_mapping[virt_to_pfn(va)] = mfn;
-
- /* build multi call */
- call[i].op = __HYPERVISOR_update_va_mapping;
- call[i].args[arg++] = va;
-#ifdef __x86_64__
- call[i].args[arg++] = (pgentry_t)pte.pte;
-#else
- call[i].args[arg++] = pte.pte_low;
- call[i].args[arg++] = pte.pte_high;
-#endif
- call[i].args[arg++] = UVMF_INVLPG;
- }
- ret = HYPERVISOR_multicall(call, i);
- if ( ret )
- {
- printk("update_va_mapping hypercall no. 2 failed with rc=%d.\n", ret);
- return 0;
- }
-
- if ( !exch_success )
- {
- /* since the exchanged failed we just free the pages as well */
- free_pages((void *) in_va, order);
- return 0;
- }
-
- return in_va;
-}
-
/*
* Clear some of the bootstrap memory
*/